1. Field of the Invention
The present invention relates to the field of interconnecting devices for data communication. More particularly, the invention relates to an interconnecting device being a part of a communication path, for allowing the transmission of high rate data signals over the communication path.
2. Prior Art
The number of devices and systems capable of exchanging high-rate digital data (i.e. wideband signals) is growing rapidly. Such systems are, for example, computers/LAN and WAN networks, telecommunication systems and Internet oriented devices. A major problem exists whenever a high-rate data signal is forwarded through a (physical) channel. The problem with physical channels originally designed for relatively low rate data signals, is that at higher data rates (i.e., at higher frequencies) the data signals become distorted and attenuated due to energy losses and parasitic effects. This problem becomes acute whenever the physical channel includes an interconnecting device for interconnecting between two data devices. This phenomenon is due to impedance mismatches between the devices and cross-talk interference between their corresponding transmission lines, resulting, e.g., in increased reflected energy (i.e. energy losses) and deterioration in the quality of data signals. In case when the communication path comprises differential transmission line, the balance of the differential lines is also deteriorated due to these parasitic effects.
Currently, there are several interconnecting devices being utilized as part of transmission lines, which have been designed to allow data devices to exchange data signals at rates that correspond to a bandwidth up to 100 MHz. Usually, such transmission lines involve interconnecting devices that are based on a cord having an input plug/jack connector on each of its ends (e.g. an RJ45 standard interconnecting device). Such interconnecting devices are associated with compensation means for allowing two high rate data devices (operating within 100 MHz bandwidth) to exchange data signals through the interconnecting devices without substantially deteriorating the quality of the data signal. However, attempts have been made to use switches as interconnecting devices in frequency bandwidth higher than 100 MHz, which resulted in sever deterioration in the data signal passing through such switches within this bandwidth.
It would be desirable to utilize a switch as an interconnecting device for interconnecting high-rate data devices (over 100 MHz), since a switch might be implemented as a micro switch, thereby reducing installation dimensions. Moreover, a switch might be an electronic switch, thereby allowing its operation by a local, or remote, controller.
FIG. 1 (prior art) illustrates a conventional interconnect device contained in an interconnect panel 13, for interconnecting two data systems 11 and 12. As described before, a conventional data path comprises transmission line segments E and A, RJ45 cord 15 and transmission line segments D and F is capable of forwarding data signals at bandwidth up to 100 MHz. Switch 14, on the other hand, has introduced significant parasitic elements that caused impedance mismatches, mutual interference between adjacent transmission lines (i.e. cross talk) and transmission lines were taken out of balance. Consequently, switch 14 has deteriorated the bandwidth to be less than 100 MHz. Wiring blocks 16a and 16b are utilized for affixing electric wires onto a Printed Circuit Board (PCB) so that each wire is electrically connected to its corresponding conductive strip on the PCB. These wiring blocks contain a plurality of Insulation Displacement Contact (IDC), one side of which is used for accepting an individual insulated electrical wire contained in, e.g., transmission lines E and F, and another side of which is soldered to the PCB (such wiring blocks are illustrated, for example, in WWW.SIEMON.COM).
Using a conventional (i.e. relatively low data rate) switch at higher frequencies deteriorates the characteristics of the matched system, since a conventional switch has lumped characteristics only in cases where low rate data signals are involved, otherwise it introduces a rather random impedance characteristic due to its parasitic capacitance(s) and/or inductance(s) at higher frequencies. Consequently, the necessary condition of ‘matched lines’ will no longer exist whenever conventional switches are used for switching high rate data signals.
All of the methods described above have not yet provided satisfactory solutions to the problem of utilizing a switch, whether as a sole device or in combination with a cord-based interconnecting device, for forwarding high-rate data signals.